This document discusses four student ID numbers and their checksum values. It explains how to calculate the checksum using a formula that assigns numeric values to each character in the ID, sums them, and uses the remainder when divided by 11 to validate the ID number. The checksum is the remainder. This allows one to identify invalid student ID numbers.

1. “
”
1.
2
3.

2. “
”
A
B C
D

3. “
”
1.ABCD
360
2.
3.
1

4. “
”1
A
B C
D
B
D
ABD
BCD
ABD +
BCD
4

5. “
”1
A
B C
D
A
C
ABC
ACD
ABC +

6. “
”
A
B C
D
F
2
1. 5
BFC
2.
n
n
180 n-2
3. 5
180 n-2 =
180 5-2 = 180 3
5

7. “
”
3 High
Light!!!
A
B C
D
E
FG
H
1
12
3
90
-1
90
-2
90
-3
1. ABCD
ABG ,
ADE ,
DEH , CDF
DEH
DFC
H = 1 = C
DEH=

8. “
”
3 High
Light!!! 3.
ABG B =
2
ABG=
BAG = 180 -
90 - 2
BAG = 90 - 2
4.
ADE ADE
= 3
A
B C
D
E
FG
H
1
12
3
90
-1
90
-2
90
-3

9. “
”
3 High
Light!!!
A
B C
D
E
FG
H
1
12
3
90
-1
90
-2
90
-3
5. AEFG
GAE = 90
A B C D
=[BAG+GAE+DAE] ABG
DCF [ADE+EDH]
=[(90 -2)+90 +(90 -
3)]+2+1+[3+(90 -1)]
= 90 + 90 + 90 + 90
= 360

10. “
”1.
-
-
20

11. “
”2.
-
-
1.

12. “
”-
-
3.
:
-

13. “
”-
:
-
-
-

14. “
” :
-
-
-

15. “
”4.
Ideas
3

16. “
”
1.
553050113-8
2.
553050271-0
3.
553050286-7
4.
553050324-6